Collapsible carton



1955 B. A. RAFOTH ET AL 2,716,519

COLLAPS IBLE CARTON Filed March 16, 1953 5 Sheets-Sheet l genn/e 6/6 7%60/86 6 Adm/do Aug. 30, 1 B. A. RAFOTH ET AL 2,716,519

COLLAPSIBLE CARTON Filed March 16, 1953 3 Sheets-Sheet 2 B. A. RAFOTH ETAL COLLAPSIBLE CARTON Aug. 30, 1955 3 Sheets-Sheet 3 Filed March 16,1953 United States Patent O COLLAPSIBLE CARTON Bennie A. Rafoth,Appleton, and George E. Wanda, Neenah, Wis., assignors to MarathonCorporatlon, Menasha, Wis., a corporation of Wisconsin Application March16, 1953, Serial No. 342,656

2 Claims. (Cl. 22939) This invention relates to collapsible paperboardcartons, of the type having what is known as an automatic bottom. Inthis construction, one end, such as the bottom, is so formed that whenthe carton is shaped from its collapsed shipping form into tube form forreceiving a product to be contained, the bottom of the cartonautomatically assumes the position to close the end of the carton. Suchconstruction eliminates the need for automatic machinery to close thatone end of the carton, or on the other hand speeds up hand erection ofthe carton by eliminating the need for separately closing one end of thecarton. sort, having an automatic" bottom, have found wide use andacceptance, particularly in the ice cream industry.

Several difficulties exist in many of these automatic bottomconstructions. In some instances the construc tion provided falls shortof being substantially leakproof, which is a prime requirement in thecase of many products to be contained, such as ice cream. In othercases, the bottom of the carton tends to collapse into the foldedposition quite as easily as it was set up into the open position, whichin the case of high-speed filling operations, is a serious drawback, anincident of a collapsed carton causing considerable slowing of theentire filling line operation. In other instances, particular bottomconstructions may fail to give the desired neat and attractiveappearance which has become such an important factor in modernpackaging.

Our invention provides a construction which results in a firm and strongcarton bottom of a substantially leakproof nature, and which is markedlyneat and attractive as presented to the purchaser of a product to becontained therein. The objects and decided advantages of our inventionwill be readily apparent from the following description and theaccompanying drawings, in' which:

Figure 1 is a plan view of the paperboard blank from which our carton isformed, viewing that surface of the blank which will become the innersurface of the finished carton,

Figure 2 is a plan view, partially cut away, similar to Figure l, butwith certain portions of the blank in folded position,

Figure 3 is a side elevation of the finished carton in collapsedcondition,

Figure 4 is a perspective view, partially cut away, show- Due to theseadvantages, cartons of this Patented Aug. 30, 1955 "ice 2 illustrated inFigure 3 into the finished carton of Figure 7, and

Figure 9 is a perspective view of our carton in position for fillingwith the product to be packaged.

Referring first to Figure 1, it is seen that our carton is formed from asingle blank of paperboard or like material, suitably cut and scoredinto a number of walls, panels, flaps and tabs, including side walls 10,11, 12 and 13 hinged together along score lines 14, 15 and 16,respectively. In the carton-erected condition, these side walls willform a rectangular sleeve (see Figures 7 and 9). Bottom end flaps 17,18, 19 and 20 are hingedly connected to walls 10, 11, 12 and 13 alongscore lines 21, 22, 23 and 24, all respectively.

Top end flaps 25, 26, 27 and 28 are hinged to the opposite end edges ofwalls 10, 11, 12 and 13 along score lines 29, 30, 31 and 32, allrespectively. Tear flapv 33 is hingedly connected to the free side edgeof side wall 10 along score line 34, and is divided by longitudinalscore line 35 into an inner panel 36 and an outer panel 37.

Bottom end flaps 18 and 20 are diagonally divided as Q by substantiallyparallel perforated score lines 40 and 41 into first or inner panels 42and 43 and outer glue panels 44 and45, all respectively. The remote edgeof bottom end flap 17 has a V-shaped notch or cut-out therein, as at 46and 47, and at the apex of the notch a cut line or slit 48 extendsinteriorly of flap 17.

Top end flap 26 has a male closing element or tab 49 formed on itsremote end, and top end flap 28 has formed interiorly thereof a femalelocking slit 50. These elements are of a conventional form, and serve toclose the top end of the filled container in a conventional manner, andneed not be described in further detail here.

The upper surfaces (Figure 1) of glue panels 44 and 45 have a suitableadhesive applied thereto, which operation may be performed byconventional automatic machinery. A similar adhesive is applied to innerpanel 36 of tear flap 33. This adhesive may be of any of the well knowntypes suitable for our purposes.

Theinitial step in the folding and adhering of our carton is illustratedin Figure 2. Bottom flaps 17, 18, 19 and 20 are folded upwardly andinwardly to overlie the upper surfaces of walls 10, 11, 12 and 13,respectively. As will be recalled, this upper surface of the blankisthat surface which will eventually comprise the inner surface of thefinished carton. Glue panels 44 and 45,are then folded upwardly andoutwardly along score lines and 41 to overlie whatwas originally thebottom surfaces of inner panels 42 and 43, all respectively, thus againpositioning upwardly the adhesive surfaces of panels 44 and as seen inFigure 2.

Wall 13, carrying with it flaps 20, and 28, is then folded upwardly andinwardly to overlie wall 12, thus bringingthe adhesive surface of gluepanel 45 into contact with that area of flap 19 which is bounded bybroken lines 50 and 51 and score line 23. Wall 10, carrying with it endflaps 17 and 25 and tear flap 33, is then folded upwardly and inwardlyto overlie wall 11 and the nearer portion of wall 12, thus bringing thatportion of bottom end flap 17 defined by broken lines 52 and 53 andscore line 21 into contact with the adhesive surface of glue panel 44.Also, this latter folding brings tear flap 33 into overlyingrelationship with what was originally the bottom surface of wall 13adjacent the free edge of that wall, and brings the adhesive surface ofinner panel 36 into contact with side wall 13 immediately adjacent thefree edge of that side wall. Pressure can then be applied to thethus-folded carton blank to obtain a secure adhesive bond at the contactpoints of the various adhesive surfaces previously mentioned. Theadhesive conarrears nections between the various bottom end flaps arefurther illustrated in Figures 4 and 5 and the result of the operationjust described is illustrated in Figure 3, which shows the collapsedcarton as it is usually constructed by the carton manufacturer forshipment to the packer of the'product to be packaged.

Referring to Figures 6, 7 and 8, the collapsed carton shown in Figure 3is set up into position for receiving the product to be packaged byapplying compressive pressure at the corners of the carton along scorelines 14 and 16. With particular reference to Figure 8, as this pressureis applied, the distance between walls 12 and 13 and between Walls and11 tends to increase, whereupon the truss construction created by theconnection of flap 19 to flap and of flap 17 to flap 18 causes theex'er- A else of forces tending to pull those bottom flaps from theirfiat position within the collapsed carton into a position perpendicularto the side walls to close the bottom end of the carton. The dimensionsof these bottom il'aps are such that flaps 18 and 20 lie to the exteriorof the erected carton, flap 17 is an intermediate position, and fiap 19to the interior of the carton. Flap 19 is of such dimensions that itclosely fits the interior of the squared or set-up carton, therebysubstantially sealing the bottom end of the carton, flap 19 beingrestrained from collapse due to the contained product by theinterrelated support of the other three bottom flaps.

As the carton is being erected (Figure 8), cut away curved edge 60 offlap 20 overrides the adjacent portion of ilap 17, tending to resist theerection of that portion of flap 17. This results in an opening-up ofcut 48, into which a portion of panel 43 of flap 20 is forced as will benoted later. Flap 18 is cut away as at edge 61 to avoid undesirableinterference between flaps '18 and 19 as the carton is erected orassembled. it will be noted from Figure 1 that it is the correspondingedges of flaps 18 and 20 which are cut away as at 61 and 60,respectively.

With particular reference to Figures 6 and 7, it will be noted that inthe erected carton bottom end flap 1 8 lies completely exteriorly of theassembled carton. Flap 20 likewise lies exteriorly of the carton exceptfor a 1'7, 18 and 20, and is supported thereby. It will be noted thatout line 48 facilitates a particularly strong, effective interlockbetween flaps 17 and panel 43 of flap 20, resisting any tendency of thecontents of the carton to push out "or break the thus-formed cartonbottom, but without there being any tendency for this construction toprovide a point of leakage for the contained product, since the mainclosure flap, flap 19, lies interiorly of this construction. It will beobserved that panel 43 of flap 20 is hinged to wall 13, which is atright angles (Figure 6) to the wall It to which 'flap 17 is hinged;while panel of flap 20 (being glued to flap 19) is elfectively integralwith flap 19 and thus hinged to wall 12. It is apparent that thisarrangement results in a truss effect between flap 17 and panel 43,which strongly resist forces within the carton tending to break thebottom open; the interlock at out line 48 of flap 20 and panel 43imposes a shear or bending stress on those elements, when they areresisting such forces, since the portion of panel 43 adjacent hinge line24 lies exteriorly (Figure 6) of the adjacent portion of flap 17 Whilethe remote portion of panel 43 lies interiorly of the distant part offlap 17 beyond cut line 48, out line 48 serving as a fulcrum for theimposition of bending stress on panel 43. On the other hand, if theinterlock were between flap 1'7 and flap 19 or panel 45 glued-to andintegral with flap '19, such a load would impose a tearing stress, whichthe paperboard carton material is much less capable of resisting.

Figure 9 shows our completed carton in the upright position ready forreceiving the product to be packaged. Referring to Figures 7 and 9, itwill be seen that our carton provides a neat and attractive, as well asstrong, packaging medium. Referring also to Figure 6, it will be seenthat tear fiap 33 provides a convenient means of opening the package.After opening the interlocked end flaps 26 and 28 the non-adhered outerpanel 37 of the tear flap 33 may be readily grasped for the breakingloose of the adhesive connection between inner panel 36 and side wall13. Walls 10 and 11 are then swung together on hinge line 15 therebyfully exposing the contents of the carton. Of course, the top end of thecarton may be opened as illustrated in Figure 9 as an alternative meansof access to the packaged material.

Since a number of variations in detail might be availed of withoutdeparting from the spirit of our invention, it is to be understood thatno limitations upon the scope of our invention are intended except asare specifically included in the appended claims.

We claim:

1. A paperboard blank for forming a collapsible carton comprising asingle blank suitably cut and scored to provide opposed pairs of cartonside walls arranged to form a rectangular sleeve when folded andconnected, each of said side walls having hingedly connected to thebottom end edge thereof a bottom flap, said bottom flaps being adaptedto form a bottom closure for the carton when secured together and thecarton side walls are formed into such sleeve, one alternate pair ofsaid bottorn flaps each being scored diagonally and in the samedirection to provide a bottom glue panel hinged to a bottom flap alongsuch diagonal score line, each of said glue panels extending toward adifferent one of the other alternate pair of bottom flaps and having itssurface which will lie to the interior of the carton adapted to beadhered to that surface of the bottom flap toward which it extends whichwill lie to the exterior of the carton,

one of the bottom flaps of the other of said alternate pairs being ofdimension to substantially close the bottom end of the rectangularsleeve, and the other bottom flap of said other alternate pair having aninwardly-extending V-shaped notch in that edge thereof opposite itshinge connection to a side wall and a slit extending inwardly from theapex of the notch, a "bottom flap of said one alternate pair beingadapted to interlock within said notch and said slit when the blank isassembled to form said sleeve and bottom closure.

2. A collapsible carton formed from a unitary paperboard blank suitablycut and scored to provide four 'consecutively-positioned side wallsadapted to form a rectangular sleeve in folded and connected condition,each of said side walls having a bottom end flap hinged to its bottomend edge, said flaps being adapted to form a bottom end closure for saidsleeve, one alternate pair of said flaps being divided by substantiallyparallel diagonal score lines into first panels hinged to the side wallsand glue panels hinged to the first panels along said score lines, eachof said glue panels extending toward a different flap from the otheralternate pair and adhered to the outer surface thereof, correspondingside edges of said first panels being substantially cut away outwardlyof the hinge-connections of those panels to the respective side walls,one of the flaps of said other'a'lternate pair being of dimension tosubstantially close the bottom end of the rectangular sleeve, and theother 'flap of said other alternate pair having an inwardly-extendingV-shaped notch cut into itsedge opposite its hinge connection to a sidewall and an inwardly-directed slit extending from the apex of saidnotch, the first panel to References Cited in the file of this patentwhich is hinged the glue panel which is adhered to said UNITED STATESPATENTS one flap of the other alternate pair being in carton-erectedposition interlocked within said notch and slit with the 2454-475 2"" P1939 portion of said first panel adjacent its hinge 'connec- 5 2327709Hlmes 1943 tion to a side wall lying exteriorly and a remote portion2'348'378 Goodyear May 1944 thereof lying interiorly of the other flapof said other 13979 June 1.950 alternate pain 2,538,860 1 Buttery Jan.23, 1951

